axiom-profile-performance

axiom-profile-performance is a skill for Codex from CharlesWiltgen/Axiom. It costs 25 tokens per session (2,631 once invoked), scanned C, original, MIT.

An automated performance-profiling helper for Apple apps that collects and analyses Instruments traces from the command line. Instruments is Apple's tool for measuring app behaviour such as CPU and memory use.

In plain words
What is it for?
It checks profiling prerequisites, records traces without a graphical interface, attributes findings to app code where supported, and produces an actionable report.
Why use it?
It separates measured findings from cases where a metric could not be collected, reducing the risk of treating incomplete profiling as a clean result.

Skill for Codex

Written for Codex: agents/openai.yaml present. Also seen: mentions CLAUDE.md; mentions Claude Code.

Good fit It checks profiling prerequisites, records traces without a graphical interface, attributes findings to app code where supported, and produces an actionable report.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/charleswiltgen/axiom/axiom-profile-performance
About the project

Axiom is a toolkit of instructions, agents, commands, and development tools that give coding assistants specialized guidance for Apple operating-system development. It covers Swift, SwiftUI, interface design, data, concurrency, performance, networking, accessibility, logging, crash analysis, simulator testing, and profiling for iOS, iPadOS, watchOS, and tvOS. The catalogue contains 42 agents, 16 commands, and one plugin from this toolkit.

CharlesWiltgen/Axiom · 1,155 stars · on GitHub · charleswiltgen.github.io

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add CharlesWiltgen/Axiom --skill axiom-profile-performance
Clone the repo
git clone --depth 1 https://github.com/CharlesWiltgen/Axiom

Made for: Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for axiom-profile-performance

README.md
[![agentmods](https://agentmods.dev/badge/skills/charleswiltgen/axiom/axiom-profile-performance/github.svg)](https://agentmods.dev/skills/charleswiltgen/axiom/axiom-profile-performance)
Your own site
<a href="https://agentmods.dev/skills/charleswiltgen/axiom/axiom-profile-performance"><img src="https://agentmods.dev/badge/skills/charleswiltgen/axiom/axiom-profile-performance/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for axiom-profile-performance

Your own site · 80×15
<a href="https://agentmods.dev/skills/charleswiltgen/axiom/axiom-profile-performance"><img src="https://agentmods.dev/badge/skills/charleswiltgen/axiom/axiom-profile-performance.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 25 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,631 The whole file, excluding the scripts and references it only reads on demand.
Security scan C 1 finding. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 1 finding, up to high

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • high Memory Poisoning · line 54
    Skill manipulates agent memory, state, or stored context. Memory corruption can alter personality, override safety rules, or cause unpredictable behavior.
    Fix: Protect agent memory and state from modification by untrusted content. Use read-only memory for critical instructions and validate all state changes.
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00025 $0.02631
Opus 5 $0.00013 $0.01316
Sonnet 5 $0.00005 $0.00526
Haiku 4.5 $0.00003 $0.00263

Measured 6d ago against content hash 5c44d756ab3c, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade C, and why

axiom-profile-performance scanned grade C with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 6d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Recursive force deletehighDestructive command

rm -rf with a variable or a broad path is one typo away from removing the wrong tree.

**Do not `rm -rf` trace directories** (CLAUDE.md S-3). Report the saved path and let the user delete, or remove a single named trace you created only with explicit confirmation. Recording into `XCPROF_TRACE_ROOT` keeps t
axiom-codex/skills/axiom-profile-performance/SKILL.md · 167 lines

How it starts

The opening of the file, as written. The whole thing — 167 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Note: This audit may use Bash commands to run builds, tests, or CLI tools.

Performance Profiler Agent

You profile apps headlessly and turn the result into an honest, actionable report. You lean on xcprof for the mechanics — bounded/gated recording, back-reference resolution, user-code attribution, and an honest per-family support matrix — and spend your attention on what the user should actually fix.

Core Principle

Measure honestly, then attribute to user code. xcprof never reports "no findings" when it means "couldn't measure" — it emits a per-family support matrix (available / partial / not_exportable / not_present). Read that matrix before you call anything clean. And never hand-grep exported XML: xcprof analyze --json has already resolved the id/ref back-references that defeat grep and filtered system frames from app code.

Prerequisites

command -v xcprof && xcprof doctor

doctor verifies xcrun xctrace and counts instruments/devices — exit 0 ready, 2 if xctrace is missing. If xcprof is absent (older Axiom install), tell the user to update Axiom and fall back to the raw CLI documented in axiom-performance (skills/xctrace-ref.md) — do not re-introduce a grep-the-XML pipeline.

Record into a session sandbox so traces are contained and the output gate is satisfied:

export XCPROF_TRACE_ROOT="$(mktemp -d)"

Workflow

1. Pick a target

Find a booted simulator and a running app. Ask the user only when it's ambiguous.

xcrun simctl list devices booted -j | jq -r '.devices|to_entries[]|.value[]|"\(.name) (\(.udid))"'
BOOTED=$(xcrun simctl list devices booted -j | jq -r '.devices|to_entries[]|.value[0].udid // empty' | head -1)
[ -n "$BOOTED" ] && xcrun simctl spawn "$BOOTED" launchctl list 2>/dev/null | grep UIKitApplication | head -10
  • App running in a booted sim → attach to it (the common case).
  • Multiple sims / no app named → ask which target.
  • Nothing booted → offer to profile a Mac app or boot a sim.

Read the full file on GitHub · 167 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 6d ago First seen · 167 lines · 25 tokens per session scan C 5c44d756ab3c

Subscribe to this mod's changes

axiom-profile-performance is a skill published in the GitHub repository CharlesWiltgen/Axiom (1,155 stars, last pushed 3d ago), licensed MIT. It adds 25 tokens to every session and 2,631 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it C with 1 finding (recursive force delete). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-06.

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